Apparatus for the production of alternating currents



J. L. MILTON.

APPARATUS FOR THE PRODUCTION OF ALTERNATING CURRENTS.

APPLICATION FILED JAN.30. 1909. RENEWED JAN. 20. l9l9.

1,366,475. Patented Jan. 25,1921.

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APPARATUS FOR THE PRODUCTION OF ALTERNATING CURRENTS.

APPLICATION FILED JAN. 30, 1909. RENEWED JAN. 20, 1919.

1,366,475. Patented Jan. 25, 1921.

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APPARATUS FOR THE PRODUCTION OF ALTERNATING CURRENTS.

APPLICATiON FILED JAN. 30, I909- RENEWED JAN. 20. 1919.

ammed Jan. 25, 19211.

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I. L. MILTON.

APPARATUS FOR THE PRODUCTION OF ALTERNATING CURRENTS.

APPLICATION FILED JAN. 30, I909. RENEWED JAN. 20, I919.

1,366,475. Patented Jan. 25, 1921.

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JOHN LEWIS MILTON, OF CLEVELAND, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO THE 'IEAGLE COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO,

APPARATUSLFOR THE PRODUCTION OF ALTERNATING CURRENTS.

Specification or Letters Patent.

Patented Jan. 25, 1921.

Application filed January 30, 1909, Serial No. 475,170. Renewed January 20, 1919. Serial No. 272,149.

To all whom it may concern:

Be it known that I, JoHN L. MILTON, a

Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented certain new and useful Improvements in Apparatus for the Production of Alternating Currents, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to apparatus for the production of alternating currents, particu-.

larly currents applicable for ignition purposes. I

One object of the invention is to provide an ignition generator in which the fixed pole parts and the cooperating rotor parts are so spaced angularly and are of such relative dimensions that the flux changes incident to the rotor movement are suitable for ignition purposes, especially in conjunction with a special pole structure such as referred to.

below. V

Another object of the invention is to provide an ignition generator having one or more poles inherently constructed and qualified to modify change of the magnetic flux linking through the said pole or poles and a generating winding inductively related thereto, so as to make the said flux change more gradual during certain parts and more rapid during other parts of the relative rotation than would result from a continuous and uniform polar projection. Such a control and modification of the flux variation can be secured by different forms of pole structure and can be used advantageously- I to modify the electro-motive force wave in various ways and for various purposes in the generation of ignition currents. In the generator shown a form of pole construction is used which gives an electromotive force wave .fo'rm adapted to produce an effective ignition spark and advantageous where the field is energized by permanent magnets, said pole construction being also adapted for use in conjunction with the first feature above mentioned so that each supplements the other.

A further object ofthe invention is to provide a mounting for both the stationary field and the rotatable armature upon one shaft, whereby it is impossible for the rotor to get out of alinement with. the polar projections. In this way binding of the rotor is effectively prevented, for the reason that no matter how much wear there is in the bearin s between citizen of the United States, residing at g inductor remain unaltered.

The manner in which the foregoing and other-objects are attained and their significanoe Wlll become fully apparent as the specification proceeds.

Referring to the drawings, wherein like numerals indicate corresponding parts in the views representing the same form or m0di-- fication,

F1gure l is a more or less diagrammatic view of my new form of inductor alternator, showing the arrangement of the pole pieces with respect to the inductor, and also showmg the polar projections provided with JlOSBd-CIICUlt conductors. In this view the nductor is shown in two positions, one being Indicated in full lines, and the other in dotted lines;

Fig. 2 is a cross-sectional view on line 22, Fig. 1;

Fig. 3 is a fragmentary view showing the position of the inductor at a certain point in its movement;

Fig. 4 is another fragmentary view showing the position of the inductor just prior to the moment of interruption of the circuit;

Fig. 5 1s a cross-sectional View of my novel arrangement of mounting the field frame anplt the'farmature upon one shaft for sup- P i Fig. 6 is a'detail view, partly in cross-sect1on,jshow1ng the disposition of the distributer arm relative to the cooperating terminals which are connected with the spark plugs of the engine cylinders;

Fig. 7 is a more or less diagrammatic view of a modified form of inductor alternator embodyingsome of my improvements;

in rough approximation of the instantaneous values of magnetic flux through either or both of the generating coils together with a corresponding representation of the instantaneous values of electro -motive force generated in the coils.

I shall first refer to the form of generator shown in Figs. 1 to 4, inclusive, of the drawings.

The permanent ma nets 59 have their like poles connected toget er by magnetic members or pole pieces 60 and 61, the pole piece 60 being provided with a pair of polar projections 62 and 63, and the pole piece 61 being provided with a pair of polar projections 64 and 65. Between the polar projections on each pole piece is a winding 66, although it is apparent that only one of the pole pieces need be provided with a winding. These four polar projections are provided with polar surfaces or areas arranged in the arc of a circle, and an inductor 67 is mounted to rotate in proximity to the polar areas so as to vary the distribution of the magnetic flux through the field frame. It will be observed that the width of the inductor is less than the distance between adjacent sides of the like polar projections 62, 63 or 64, 65, but is greater than the distance between the adjacent unlike polar projections 62, 64 or 63, 65. The purpose of this arrangement of the pole pieces with respect to the inductor is to cause the inductor to open the magnetic circuit during certain intervals, that is to say, when the inductor is in a horizontal position; but to cause a graduated variation of the magnetic flux during those intervals in which the inductor spans the adjacent unlike polar projections 62, 64 and 63, 65.

It is clear from Figs. 1 and 3 that the inductor does not break the magnetic circuit in passing from the polar projections 62, 65 to the polar projections 64, 63, but. the flux is gradually shifted from the first pair of polar projections to the second pair. In consequence, the reversal of flux through the windings during this movement of the inductor takes place in a gradual manner with the result that a wave of comparatively low electro-motive force is generated. When, however, the inductor passes from the polar projections 64 and 63 as shown in Fig. 4 to the polar projections 65 and 62 as shown in Fig. 1, the inductor breaks the magnetic circuit and immediately causes a very sudden reversal of the flux through the windings. The wave of ele'ctro-motive force generated during this movement of the inductorwillreach a comparatively high value and it is this negative half wave of high electro-motive force which is used for the ignition of the charge in the engine cylinders. The peak of the negative half wave is probably reached at the instant when the It will be observed that in Figs. 1, 3 and 4, the polar projections 62, 63, 64 and 65 are provided near their extremities with closed-circuit conductors, indicated respectively by 68, 69, 70 and 71. Each one of the pole pieces is in its polar area provided with a slot 72 terminating in an enlarged opening 73 in which rests one portion of the closedcircuit conductor. In the particular in-. stance illustrated, these conductors would be secured in place by threading them through the opening 73 and then soldering the free ends together. Of course various other ways may be used for fixing the conductors'to the pole pieces, depending upon the shape and size of the conductor and the slot in the pole piece. These conductors may be simply copper. bands, which it is not necessary to insulate from the metal of the pole pieces, for the reason that copper is non-magnetic. The purpose and function of these closedcircuit conductors depends upon what is known as the law of Lenz, which may be stated to be that in all cases of electro-magnetic induction,the induced currents have a direction such that their reaction tends to stop the motion which produces them. To apply this to a concrete case, let us follow the movements of the inductor as shown in Figs. 1, 3 and 4. lVe have already followed these movements when we were considering the width of the inductor as compared with the distance between like and unlike polar projections. In that case, however, we purposely omitted the closed circuit conductors so that we shall now take into consideration the effect which these closed-circuit conductors have on the variation of the flux distribution as the inductor revolves. When theinductor is in the position indicated in full lines in Fig. 1, the magnetic circuit is about to be substantially short-circuited through the polar projections 62 and 65. As is'evident this will cause a sudden increase in the number of magnetic lines through the windings, thereby generating therein an electro-motive force in the negative direction. So long as the forwardly jmov'ing ends of the inductor remain opposite these polar areas of the projections 62 and 65 which are not encircled by the cl0sed-circuit conductors, this increase of the magnetic flux through the windings will take place unimpeded by the retarding influence of the closed conductors. However, as soon as the inductor has begun to span the polar areas which are encircled by the closed conductors 68 and 71. the variation of the magnetic flux through the polar projections 62 and 65 will be interfered with or dampened. This is due to the fact that as soon as the inductor is in position to afford a patlrof low reluctance across the polar areas which are encircled by the closed conductors, the variations of magnetic flux through these polar areas will set up in the closed conductors currents which, owing to the low resistance of the conductors, reaches a considerable value. Now, the direction of these currents is such as to oppose any variation in the magnetic flux through the polar areas which the conductors encircle. This is in aceerdanoe with the law of Lenz, as above stated. It may, therefore, be truly said that those portions of the polar projections Which are surrounded by the closedcircuit conductors are shaded against magnetic variations, for which reason I shall hereafter refer to such portions of the polar projections as the shaded portions, while those portions of the polar projections which are not encircled by closed conductors,

. will be referred to as the unshaded portions.

The effect of the short-circuited conductors 68, 69, and 71 will be readilyunderstood by following the movement of the inductor 67 through 180 from the position shown in Fig. 1. As soon as the upper and lower front edges of the inductor pass the notches 72 in the polar projections 62 and 65, a flux path begins to open through the copper rings 68 and 71; but the currents thus induced in the said conductors tend to oppose increase of flux through the conductors, and increase of flux through the polar projections 62 and 65 and similarly through the generat ing windings 66, is correspondingly retarded. An analogous action takes place as the front edges of the inductor come adjacent the polar projections 64 and 63, as the rotary movement continues. On the other hand, as the rear edges of the inductor pass from under the shaded parts of the stationary pole pieces, the resulting decrease in the flux through said parts of the pole pieces, by virtue of the currents induced by such decrease, is retarded. Thus as the rear edges of the inductor leave the shaded parts of the polar projections 62 and 65, the flux through the shaded tips of these projections is sustained 'after the rear edges of the inductor have moved a substantial distance away from the pole tips, the effect being to increase the angular movement of the inductor during which flux changes through the polar projections 62 and 65 take place. The action as the rear edgesbf theinductor pass away from the shaded ,parts of the polar projections 64 and 63 tends in an analogous manner to extend the period of flux change through the short-circ'uited conductors 70 and 69 while the retreating edges of the inductor are passing opposite the unshaded parts of polar projections 64 and 63. The

result of this latter dampening of the flux is to cause a part of the flux change incident to the passage of the rear edges of the inductor past the shaded parts of polar projections 64 and 63 to occur during the passage of said rear edges past the unshaded parts ofsaid projections so that the rate of. flux decrease during the latter passage and just prior to the opening of the magnetic circuit, is materially increased, with the resultant generation of a negative electromotive force wave of high value. Thus, it will be seen, the effect of the short-circuited I conductors, as the inductor moves through a cycle of operations, is to render the flux change more gradual during part of the movement and more rapid during another part of the movement than would result from a continuous and uniform polar projection. It'is these effects of the short-circuited conductors on the variation of the flux that I have referred to as a dampening of the change of flux. I

From the foregoing description it will be clear that while the shading of parts of the pole pieces and the relative spacing and dimensions of the rotor and stator polar faces constitute features that are independently useful, they. are also well adapted for co-- operative use. i i

Fig. 11 diagrammatically represents a more or less rough approximation of the variations in magnetic fiux through the cores of the generating coils, taking into account the effect both of the short-circuited conductors on the polar projections and the relative dimensions and spacing of the inductor and said projections. The diagram represents the variations during a full revolution of the inductor starting from a horizontal position. The full line a.of this Fig.

11 represents instantaneous values of the magnetic flux, while the dotted line b represents corresponding values of the electro-- motive force generated by the change of flux from moment to moment, the curves starting with the inductor in a horizontal position.

As the inductor advances from its horizontal position the flux through the generating winding first increases as indicated by curve 0: with the generation of a corresponding electro-motive force wave b, which is arbitrarily shown as negative. Theflux then decreases to zero and increases in the opposite direction, generating the positive electro-motive force wave 6 and, as the inductor again approaches a horizontal position, the flux rapidly decreases to zero, generating the maximum electro motive force wave 6 This completes one cycle of the operation 12 the that the closed-circuit conductors may "be arranged in various ways upon the polar pro ections, depending upon the particular effect which it is desired to produce.

For instance, instead of shading approxh mately one-half of each polar projection, as shown in the drawings, a greater or smaller portion of each polar projection may be thus shaded. Ur, it may be found desirable to shade certain polar projections entirely. Besides this, different effects may be produced by varying the distance between polar projections rela ive to the width of the inductor. 1n. the particular example illustrated, l have shown the inductor of greater width than the distance between adjacent unlike polar projections, but of slightly less width than the distance between the adjacent sides of like polar projections. lit is not at all necessary to adhere to this specific arrangement, as far as concerns, the invention set forth in certain of the appended claims.

In Fig. 10 have shown a modification of the construction illustrated inFig. 1. In this modification the field structure is, in addition to the main generator windings 66, provided with auxiliary coils or wvindings' 127, 127, 128 and 128, situated on the limbs of the permanent magnets. For the sake of illustration l have shown these auxiliary windings connected in series with each other and in shunt to the main windings. The connection may, however, be changed in accordance with the particular effect which it is desired to produce. For instance. the auxiliary windings may be put in shunt with each other and in series with the main winding, or the auxiliary windings may be in series with each other and with the main windings. It will be remembered that in the arrangement of closed-circuit conductors in Fig. 1, certain voltage waves are dampened or repressed, while other waves are caused to reach high values of voltage, particularly the negative half-wave which is generated at themoment the inductor 0 ens the magnetic circuit-as indicated in ig. 11. So far as concerns the effect of the generated wave of electro-motive force on the magnetic field, it follows that the preponderating effect is a magnetizing one. Therefore, by placing auxiliary coils on the magnet frame, as illustrated in Fig. 10, the generated current inpassing through these coils will produce a magnetizing effect on the field-that is to say, the flux due to the current in these coils will be in the same direction as the flux of the field itself, thus strengthening the latter.

The form of construction shown in Fig. T illustrates the fact that shading of the pole pieces and also the use of auxiliary or magnetizing coils can be applied to generators differing materially from those above described. In Fig. 7 the field structure con prises a permanent U-sha-pe magnet 74, pole pieces and 76 with polar extensions 62', 63, and 8 1-, 65 to which are fitted dampening coils 68', 69 and 70, 71, respectively, and a rotor 67. Between the polar projections is mounted a horizontally arranged generating winding 66', the arrangement being such that the field flux is caused to pass alternately in opposite directions through coil 66 by the rotation of the rotor 67. @n the limbs of magnet 74 are auxiliary coils .or windings 127 and 128 which are connected in series with each other and in shunt relation to the main winding 66. The connection may, however, be changed to put the coils in shunt with each other and in series with the main winding.

Coming now to the feature of my invention shown in Figs. 5, 8 and 9, it will be observed that from the engine casing 77 extends the shaft 78. The hub 79 of the engine casing has secured thereto the sleeve 80 in which the shaft 78 finds bearing and support. The sleeve 80 is screw-threaded into the hub of the engine casing, a nut 81 being used for tightening the sleeve in place. as well as for adjusting the same-in position on the hub. The shaft is provided with two bearing portions, one consisting of the ring 82, and the other of the ring 88. These rings are firmly secured to the shaft upon the enlarged portions 84: and 85, respectively. The ring 82 is provided with an annular groove 86, while the ring 83 is provided with an annular groove 87. The field-structure comprises two groups of oppositely disposed permanent magnets 88,-

connected together by magnetic members 89 and 90. In the instance illustrated, each of these magnetic members is provided with a pair of polar projections 91, 92 and 93, 9-1, respectively, between the polar projections on the magnetic members are carried the generator windings 95 and 96. To the polar projections, near their outer extremities, is secured the plate 97, of non-magnetic lfll) Y jections.

insects faces of the bearing rings. The bearing ring 101 is held in place by the annular member 1041, which is suitably secured to the hub of the plate 97 in order to inclose the inner portion of the field-frame in a practically dustproof casing, ll secure a non magnetic member 105 to the plate 97 by means of crews 106. This member 105 has a peripheral portion'lO'? extending axially thereof, so as to abut against the periphery .ofthe plate 97. The two members 97 and 105 thus form a non-magnetic casing in closing the inner portions of the polar proln the hub portion of the her 165 isrittedthe bearingring 108. This ring is provided with an inner peripheralgroove 109. Tn the'space betweenthe hearing rings 82 and 108 are confined the ballbearings 110 which move in the grooves of the opposing surfaces of the bearing, rings. A retaining ring 111 is secured to the member 105 to hold the bearing ring 108 in place.

From this it will be seen that the field.

. structure which is directly secured" to the plate 97 is, as awhole, supported on and from the shaft 78, which shaft is in turn supported from the engine casing. The

armature or inductor 112 is secured to the shaft to rotate within the casing in proximity to the polar projections in order to vary the distribution of the magnetic flux through the generator windings. By thus supporting the field structure and the. armature upon one and the same shaft, it will be seen that it is impossiblefor the two to get out of alinement for, no matter what wear the shaft may receive in its bearing in the engine casing, the alinement between the armature and the field is in no wise affected.

T consider this feature of my inventionof great mechanical advantage. t is well understood that to operate an inductor-alter nator mosteiliciently, the armature should move-as closely to the polar projections as mechanical conditions will permit. -rdinarily, by supporting the field structure 1ndependently of the shaft whlch carries the armature, any wear in the support or the armature shaft necessarily afiects the position of the armature with respect to the field-frame, with the result that the armature does not .move concentrically relative to the polar projections. This produces what is termed binding of the armature and seriously interferes with theproper operation of the machine, According to my construction, however, this binding of the armature cannot take place, for thereason that any alteration of position 'wh1ch the armature shaft may undergo by reason of any wear in its support affects the fieldframe and the armature alike.

Any suitable connection may be used for holding the field-frame stationary while the ply operating the lever, the field-frame would be rotated with respect to the armature, thus causing an ele'ctro-motive force to be generated in the inductor windings. Tn this way is possible to start the engine on the spark, as it is called,--that is to say,

, without cranking.

A convenient way of locating the dis trinuter would be to secure 1t to the free end of the shaft 78, as shown in Fig. 5, by

meansof the sleeve 113, which is provided with a radial flange 11d." To this flange is secured the cylindrical member 115 by means of screws 116. This cylindrical member 115 has secured thereto the distributor arm. 11? by means of the screw 118. This.

distributer arm, which is connected with one end of the generator windings, rotates with the armature in proximity to the radially arranged terminals 118, 119, 120 and 121. These terminals are mounted in the cylinder 122 of insulating material, secured to the'casing 123 by means of screws 12%. The open end of the cylinder 122 may be closed by a glass dish 125 so that the operation of the distributor may be watched. The I outer portions of the terminals are in the form of binding posts to as to permit the attachment of conductors thereto. The cylindrical casing 123 is secured to the member 105 by the bolts or screws 126. In this way the dlstributer is entirely inclosed, and therefore kept free from dust-and other injurious elements. r v

Although in describing the various features of my invention as herein set forth, l have referred to specific structures illustrated in the drawings, 1 would have it understood that such illustrations are by way of example only, and are not to be understood as limiting the scope of my invention as set forth in the appended claims. Furthermore, it will be apparent that certain features of my invention may be used inde pendently of certain other features.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is 1. In an ignition enerator, the combination of a magnetic eld structure provided with polar projections, a windlng 1n inductive relation thereto, a rotor movable 1n proximity to said polar projectionsto vary the magnetic flux through said w1nd1ng,and

closed-circuit conductors carried by said polar projections to dampen the magnetic variations through said winding during certain intervals.

2. In an ignition generator, the combination of a magnetic field structureprovlded with polar projections, a winding in inductive relation thereto, a rotor movable in proximity to said polar projections to generate in said winding an alternating electromotive force, and a closed-circuit conductor arranged on each of said polar projections to dampen certain alternate waves of the electro-motive force.

3. In an ignition generator, the combina tion of a magnetic field structure provided with four polar projections, a winding in inductive relation thereto, a rotor movable in proximity to said polar projections to vary the magnetic flux through said wlnding, and a closed-circuit conductor extending over, a portion of each polar projection to dampen the magnetic variations through said winding during certain intervals.

4. In an ignition generator, the combina tion of a magnetic field structure provided with four polar projections arranged in pairs, the polar projections of one pair being of one polarity, while the polar projections of the other pair are of the opposite polarity, a winding in inductive relation thereto, a' closed-circuit conductor extending over adjacent portions of unlike polar projections to shade said adjacent portions against magnetic variations therethrough, the adjacent portions of like polar projections being unshaded, and a rotor movable in proximity to said polar projections to generate an alternating electro-motive force in said winding, the width of said rotor being less than the greatest distance between the unshaded portions of like polar projections, whereby certain of the voltage waves generated are dampened while other Waves are caused to reach high values of voltage for ignition purposes.

5. In an ignition generator, the combination of a pair of permanent magnets, magnetic pole pieces for connecting magnet poles of like polarity, windings carried by said pole pieces, a pair of polar projections provided on each of said pole pieces, a rotor movable in proximity to said polar projections to vary the ma netic flux through said windings, and close -circuit conductors carried by said polar projections to dampen the magnetic variations through said winding during certain intervals.

6. In an ignition generator, the combination of a pair of permanent magnets, magnetic pole pieces for connecting magnet poles of like polarity, windings carried by saidpole pieces, a pair of polar projections carried on each of said pole pieces, arotor movable in proximity to said polar projections to generate in said windings an alternating electro-motive force, and a closedcircuit conductor arranged on a portion of each polar projection to dampen certain alternate waves of the electromotive force.

7. In an ignition generator, the combina tion of a magnetic structure including a permanent magnet and having relatively rotating parts, and a generating winding in inductive relation to the magnetic structure, one of said relatively moving parts having a pole structure comprising a plurality of sections disposed in angular succession around the axis of rotation, one of said sections being inherently adapted more than 0 the next section in advance of it to retard the flux change as the other relatively moving part passes in the normal operation of the generator, thereby making the flux change through the generating winding more gradual during a part of the relative rotation and correspondingly modifying the form of the resultingjelectro-motive force wave.

8. In an ignition generator, the combination of a magnetic structure including a permanent magnet and having relatively rotating parts, and a generating winding in inductive relation to the magnetic structure, one of said relatively moving parts having a pole structure comprising a plurality of sections disposed in angular succession] around the axis of rotation, one of said sec-. tions being inherently adapted more than an adjacent section to retard the flux change as the other relatively moving part passes in the normal operation of the generator, thereby makingthe flux change through the generating winding more gradual during a. part of the relative rotation and more rapid during another part of said rotation and correspondingly modifying the form of the resulting electro-motive force wave.

9. In an ignition generator, the combination of a magnetic structure including a permanent magnet and having relatively roat1ng parts, and a generating winding in inductive relation to the magnetic structure. one of said relatively moving parts having pole pleces of opposite polarity formed with a plurality of sections which are arranged in angular succession around the axis of rd tation and the adjacent pole sections of opposite polarity being inherently adapted more than .their next ad'acent sections of 12,0 similar polarity to retar the flux change as the other relatively moving part passes in the normal operation of thegenergtor, thereby making the flux change through the generating winding more gradual during a part of the relative rotation and correspondingly modifying the form of the resulting electro-motive force wave.

10. In anignition generator, the combination of a magnetic structureincluding a permanent magnet and having relatively rotating parts, and a generating winding in inductive relation to the magnetic structure 9 one of said relatively moving parts having vpole pieces of opposite polarity and each comprising a plurality of sections arranged in angular succession around the axis of rotation, a section of each pole piece being inherently adapted more than the next adjacent section of said pole piece to retard the flux change as the other relatively moving part passes in the normal operation of the generator, thereby making the rate of flux change through the generating winding more gradual during a part of the rela-. tive rotation and correspondingly modifying the form ofthe resulting electro-inotive forcewave.

11. In an inductor-alternator, the combination of a pair of permanent magnets, magnetic polepieces for connecting magnet poles of like polarity, windings carried by said pole pieces, a pair of polar projections provided on each of said pole pieces, closedcircuit conductors extending over adjacent portions of unlike polar projections to shade -said adjacent portions against magnetic variations therethrough, the adjacent portions of like polar projections being unshaded, and an inductor movable in proximity to a sa d polar projections to generate an alterhating electro-motive force in said windings, the width of said inductor being less than the greatest distance between the unshaded portions of like polar projections,

. whereby certain of the voltage waves generated are dampened while other waves are caused to reach high'values of voltage for ignition purposes.

12. An inductor-alternator comprising, in combination, a magnetic field frame provided with tour polar projections arranged in pairs, the polar projections of one pair being of one polarity, while the polar projections of the other pair are of the opposite polarity, windings on said magnetic field frame, and an inductor movable in close proximity to said polar projections, the Width of said inductor being less than the distance between like polar projections but greater than the" distance between the for connecting magnet poles of like polarity, a pair of polar projections on each of said pole pieces, a winding on one of said pole pieces between the polar projections thereof, and an inductor movable in close proximity to said polar projections, the width of said inductor being less than the distance between like polar projections but greater than the distance between the adjacent sides of unlike polar projections, whereby, at certain intervals, the inductor opens the magnetic path of the field and at other intervals establishes two magnetic paths through said polar projections, an increase in reluctance in one of said paths being accompanied by a decrease in reluctance in the other path to produce graduated variations of magnetic flux through said winding during said lastmentioned intervals.

let. An inductor-alternator comprising, in combination, a magnetic field frame provided with four polar projections arranged in pairs, the polar projections of one pair being of one polarity, while the polar projections of the other pair a re of the opposite polarity, windings on said magnetic field frame, an inductor movable in close proximity to said polar projections, the width of said inductor being less than the distance between like polar projections but greater than the distance between the adjacent sides of unlike polar projections, whereby, at certain intervals, the inductor opens the magnetic path of the field and at other intervals establishes two magnetic paths through said polar projections, an increase in reluctance in the one of said paths being accompanied by a decrease in reluctance in the other path to produce graduated variations of magnetic force through said winding during said lastmentioned intervals, and closed-circuit conductors carried by said polar projections to dampen the magnetic variations; through said winding during certain intervals.

15. An inductor-alternator co1nprising,-in combination, a pair of oppositely disposed permanent magnets, magnetic pole pieces for connecting poles of like polarity, a pair of polar pro ections on each of said pole pieces, a winding on one of said pole pieces between the polar projections, thereof, an inductor movable in close proximity to said polar projections, the width of said inductor being less than the distance between like polar projections but greater than thedistance between the adjacent sides of unlike polar projections,whereby, at certain intervals, the inductor opens the magnetic path of the field and at other intervals establishes two magnetic paths through said polar projecthrough said windings during said lastmentioned intervals, and closed-eircuit conductors carried by said polar pro ections to dampen the magnetic variations through said Winding, cl'osedcircuit conductors carried by said polar projections to dampen the magnetic variations through said Winding during certain intervals, whereby the current generated has a preponderating magnetiz- 111g en'ect on the magnetic field, and an auxiliary Winding carried by the field structure and in circuit With the main winding to subject the magnetic held to said magnetizing effect.

17. In an inductor-alternator, the combination of a suitably supported shaft, a nonmagnetic casing directly journaled thereon for support, a magnetic field frame provided with polar projections, means for supporting said field frame from said casing, said supporting means extending into said polar projections, a Winding carried by the field frame, and an inductor secured to said shaft to rotate Within the field frame for varying the magnetic flux through said 8. in an inductor-alternator, the combination of a suitably supported shaft provided With bearing portions, a magnetic field frame provided with windings and polar projections, a non-magnetic bearing member on either side of said field frame to cooperate with said bearing portions for supporting the field frame on the shaft, said bearing members constituting a casing for said polar projections, said windings being outside of the casing, and an inductor secured to said shaft to rotate therewith for vary ing the magnetic flux through said winding.

19. in an inductor-alternator, a magnetic field frame provided with windings and polar projections, a non-ma netic casing secured to said polar projections and inclosing the same at their inner extremities, a shaft, asupport therefor, an inductor mounted on said shaft and rotatable Within said casing in proximity to said polar projections, and cooperating bearing portions on said shaft and casing for supporting said iield frame on the shaft.

Ill Wllll'lQSS whereof, I hereunto subscribe my name this 22nd day of January, A. D.

GHN LEW 1S MELTQN. itnesses 2 Lnonaao W. llovannnn, A. THOMAS, 

